Hemostasis valve design for introducer sheath

ABSTRACT

A hemostasis valve for use in a medical device. The hemostasis valve may include a generally cylindrical body having a proximal side, a distal side, and a thickness extending therebetween. The proximal side may include a tapered central region having a surface sloped towards a center of the body and the distal side may include a distally extending curved central region.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional PatentApplication Ser. No. 62/419,670 filed on Nov. 9, 2016, the disclosure ofwhich is incorporated herein by reference.

TECHNICAL FIELD

The disclosure is directed to a hemostasis valve. More particularly, thedisclosure is directed to a self-centering hemostasis valve.

BACKGROUND

A wide variety of intracorporeal medical devices have been developed formedical use, for example, intravascular use. Some of these devicesinclude guidewires, catheters, and the like. These devices aremanufactured by any one of a variety of different manufacturing methodsand may be used according to any one of a variety of methods. Of theknown medical devices and methods, each has certain advantages anddisadvantages. There is an ongoing need to provide alternative medicaldevices as well as alternative methods for manufacturing and usingmedical devices.

SUMMARY

This disclosure provides design, material, manufacturing methods, anduse alternatives for medical devices.

In a first example, a hemostasis valve for use in a medical device maycomprise a generally cylindrical body designed to be disposed within ahub body of a medical device. The body may have a proximal side and adistal side. The proximal side may include a tapered central regionhaving a surface sloped towards a diametrical center of the body and thedistal side may include a distally extending curved central region.

Alternatively or additionally to any of the examples above, in anotherexample, the body may comprise an elastomeric silicone.

Alternatively or additionally to any of the examples above, in anotherexample, the body may comprise a liquid silicone rubber (LSR).

Alternatively or additionally to any of the examples above, in anotherexample, the body may comprise an enhanced tear resistant (ETR) siliconeelastomer.

Alternatively or additionally to any of the examples above, in anotherexample, the hemostasis valve may further comprise one or more slitsformed in the body and extending at least partially through the bodybetween the tapered central region and the curved central region of thebody.

Alternatively or additionally to any of the examples above, in anotherexample, the one or more slits may be formed in a cross slit thru (CST)configuration.

Alternatively or additionally to any of the examples above, in anotherexample, the one or more slits may be formed in cross slit partial (CSP)configuration.

Alternatively or additionally to any of the examples above, in anotherexample, the one or more slits may be formed in a star slit thru (SST)configuration.

Alternatively or additionally to any of the examples above, in anotherexample, wherein the tapered central region may be configured to guide asupplemental medical device to the diametrical center of the body.

Alternatively or additionally to any of the examples above, in anotherexample, the body may further comprise a flanged outer perimeter, theflanged outer perimeter configured to engage a hub body of a hemostasisvalve assembly.

In another example, a hemostasis valve assembly may comprise a hub bodydefining a cavity, a strain relief portion extending distally from thehub body, an end cap coupled to a distal end of the hub body, and ahemostasis valve positioned within the cavity of the hub body andcoupled between the hub body and the end cap. The hemostasis valve maycomprise a generally cylindrical valve body having a proximal sideincluding a tapered central region having a surface sloped towards adiametrical center of the body and a distal side including a distallyextending curved central region.

Alternatively or additionally to any of the examples above, in anotherexample, the valve body may comprise an elastomeric silicone.

Alternatively or additionally to any of the examples above, in anotherexample, the valve body may comprise a liquid silicone rubber (LSR).

Alternatively or additionally to any of the examples above, in anotherexample, the valve body may comprise an enhanced tear resistant (ETR)silicone elastomer.

Alternatively or additionally to any of the examples above, in anotherexample, the hemostasis valve assembly may further comprise one or moreslits formed in the valve body and extending at least partially throughthe valve body between the tapered central region and the curved centralregion.

In another example, a hemostasis valve for use in a medical device maycomprise a generally cylindrical body designed to be disposed within ahub body of a medical device. The body may have a proximal side and adistal side. The proximal side may include a tapered central regionhaving a surface sloped towards a diametrical center of the body and thedistal side may include a distally extending curved central region.

Alternatively or additionally to any of the examples above, in anotherexample, the body may comprise an elastomeric silicone.

Alternatively or additionally to any of the examples above, in anotherexample, the body may comprise a liquid silicone rubber (LSR).

Alternatively or additionally to any of the examples above, in anotherexample, the body may comprise an enhanced tear resistant (ETR) siliconeelastomer.

Alternatively or additionally to any of the examples above, in anotherexample, the hemostasis valve may further comprise one or more slitsformed in the body and extending at least partially through the bodybetween the tapered central region and the curved central region of thebody.

Alternatively or additionally to any of the examples above, in anotherexample, the one or more slits may be formed in a cross slit thru (CST)configuration.

Alternatively or additionally to any of the examples above, in anotherexample, the one or more slits may be formed in cross slit partial (CSP)configuration.

Alternatively or additionally to any of the examples above, in anotherexample, the one or more slits may be formed in a star slit thru (SST)configuration.

Alternatively or additionally to any of the examples above, in anotherexample, the tapered central region may be configured to guide asupplemental medical device to the diametrical center of the body.

Alternatively or additionally to any of the examples above, in anotherexample, the body may further comprise a flanged outer perimeter, theflanged outer perimeter configured to engage a hub body of a hemostasisvalve assembly.

In another example a hemostasis valve assembly may comprise a hub bodydefining a cavity, a strain relief portion extending distally from thehub body, an end cap coupled to a distal end of the hub body, and ahemostasis valve positioned within the cavity of the hub body andcoupled between the hub body and the end cap. The hemostasis valve maycomprise a generally cylindrical valve body having a proximal sideincluding a tapered central region having a surface sloped towards adiametrical center of the body and a distal side including a distallyextending curved central region.

Alternatively or additionally to any of the examples above, in anotherexample, the valve body may comprise an elastomeric silicone.

Alternatively or additionally to any of the examples above, in anotherexample, the valve body may comprise a liquid silicone rubber (LSR).

Alternatively or additionally to any of the examples above, in anotherexample, the valve body may comprise an enhanced tear resistant (ETR)silicone elastomer.

Alternatively or additionally to any of the examples above, in anotherexample, the hemostasis valve assembly may further comprise one or moreslits formed in the valve body and extending at least partially throughthe valve body between the tapered central region and the curved centralregion.

Alternatively or additionally to any of the examples above, in anotherexample, the valve body may further comprise a flanged outer perimeter,the flanged outer perimeter configured to engage an interlocking groovein the hub body.

Alternatively or additionally to any of the examples above, in anotherexample, the valve body may further comprise a first annular grooveformed in the proximal side and a second annular groove formed in thedistal side, the first annular groove configured to engage aninterlocking feature in the end cap and the second annular grooveconfigured to engage an interlocking feature in the hub body.

Alternatively or additionally to any of the examples above, in anotherexample, the tapered central region may be configured to guide a medicaldevice to the diametrical center of the valve body.

In another example a hemostasis valve assembly may comprise a hub bodydefining a cavity, a strain relief portion extending distally from thehub body, an end cap coupled to a distal end of the hub body, and ahemostasis valve positioned within the cavity of the hub body andcoupled between the hub body and the end cap. The hemostasis valve maycomprise a generally cylindrical elastomeric valve body having aproximal side and a distal side, a tapered central region having asurface sloped towards a diametrical center of the valve body on theproximal side thereof, a distally extending curved central region on thedistal side thereof, a first annular groove formed in the proximal side,a second annular groove formed in the distal side, and a flanged outerperimeter.

Alternatively or additionally to any of the examples above, in anotherexample, the hemostasis valve may further comprise one or more slitsformed in the valve body and extending at least partially through thevalve body between the tapered central region and the curved centralregion.

The above summary of some example embodiments is not intended todescribe each disclosed embodiment or every implementation of theinvention.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention may be more completely understood in consideration of thefollowing detailed description of various embodiments in connection withthe accompanying drawings, in which:

FIG. 1 is a perspective view of an illustrative vascular access system;

FIG. 2 is a cross-sectional view of the illustrative vascular accesssystem of FIG. 1, taken at line 2-2;

FIG. 3 is an enlarged cross-sectional view of the illustrativehemostasis valve assembly of FIG. 2;

FIG. 4 is a perspective view of an illustrative hemostasis valve;

FIG. 5 is a cross-sectional view of the illustrative hemostasis valve ofFIG. 3, taken at line 5-5 in FIG. 4;

FIG. 6A is a proximal end view of the illustrative hemostasis valve ofFIG. 3 having a slit configuration; and

FIG. 6B is a proximal end view of the illustrative hemostasis valve ofFIG. 3 having an alternative slit configuration.

While the invention is amenable to various modifications and alternativeforms, specifics thereof have been shown by way of example in thedrawings and will be described in detail. It should be understood,however, that the intention is not to limit aspects of the invention tothe particular embodiments described. On the contrary, the intention isto cover all modifications, equivalents, and alternatives falling withinthe spirit and scope of the invention.

DETAILED DESCRIPTION

For the following defined terms, these definitions shall be applied,unless a different definition is given in the claims or elsewhere inthis specification.

All numeric values are herein assumed to be modified by the term“about”, whether or not explicitly indicated. The term “about” generallyrefers to a range of numbers that one of skill in the art would considerequivalent to the recited value (i.e., having the same function orresult). In many instances, the term “about” may be indicative asincluding numbers that are rounded to the nearest significant figure.

The recitation of numerical ranges by endpoints includes all numberswithin that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4,and 5).

Although some suitable dimensions ranges and/or values pertaining tovarious components, features and/or specifications are disclosed, one ofskill in the art, incited by the present disclosure, would understanddesired dimensions, ranges and/or values may deviate from thoseexpressly disclosed.

As used in this specification and the appended claims, the singularforms “a”, “an”, and “the” include plural referents unless the contentclearly dictates otherwise. As used in this specification and theappended claims, the term “or” is generally employed in its senseincluding “and/or” unless the content clearly dictates otherwise.

The following detailed description should be read with reference to thedrawings in which similar elements in different drawings are numberedthe same. The detailed description and the drawings, which are notnecessarily to scale, depict illustrative embodiments and are notintended to limit the scope of the invention. The illustrativeembodiments depicted are intended only as exemplary. Selected featuresof any illustrative embodiment may be incorporated into an additionalembodiment unless clearly stated to the contrary.

FIG. 1 is a perspective view of an illustrative vascular access system10. The vascular access system 10 may be used to gain vessel accessduring a diagnostic or interventional procedure. While the system 10 isdescribed in terms of vascular access, the system 10 may be used toaccess other parts of the body. The access system 10 may include anintroducer sheath 12 and a dilator 14. The introducer sheath 12 includesan elongate shaft 16 and a hemostasis valve assembly 18. As will bedescribed in more detail herein, the hemostasis valve assembly 18 mayinclude a valve member or gasket which reduces or prevents blood losswhen the introducer sheath 12 is inserted into a vessel while allowingfor the passage of other devices (e.g., dilators, guide catheters, etc.)through the introducer sheath 12.

In some cases, the distal tip 30 of the elongate shaft 16 may be taperedto facilitate smooth insertion into the vascular system and/or toprovide a smooth transition to the dilator 14. The elongate shaft 16 ofthe introducer sheath 12 may have a size (outside diameter or profile)ranging from 4 French (F) to 9F, and a length ranging from 10centimeters (cm) to 25 cm. However, the outer diameter can be smallerthan 4F or greater than 9F. It is further contemplated that the lengthof the shaft 16 may be shorter than 10 cm or longer than 25 cm. Thehemostasis valve assembly 18 may include a hub body 20 and a strainrelief portion 22 coupled to or formed as a unitary structure with thehub body 20 and extending distally therefrom. The hub body 20 mayinclude a side port 24 for connection to a flush or injection tubesubassembly (not explicitly shown). The dilator 14 includes an elongateshaft 26 and a handle 28. It should be understood that the hemostasisvalve assembly 18, or the components thereof, may be used with othermedical devices, such as, but not limited to interventional catheters,diagnostic catheters, guide sheaths, etc.

FIG. 2 is a cross-sectional view of the illustrative vascular accesssystem 10 of FIG. 1, taken at line 2-2 in FIG. 1. The introducer sheath12 includes a lumen 32 extending from a proximal end 34 to the distaltip 30 of the elongate shaft 16. The lumen 32 may be sized to receivethe dilator 14, or other device. The hemostasis valve assembly 18 isconnected to the proximal end 34 of the shaft 16 utilizing conventionaltechniques. The dilator 14 includes a lumen 36 extending from theproximal end 38 to the distal end 40 of the elongate shaft 26. The lumen36 may be configured to receive a diagnostic or interventional device ortherapy. The handle 28 may be connected to the proximal end 38 of theelongate shaft 26 of the dilator 14 using conventional techniques.

Referring additionally to FIG. 3, which illustrates an enlargedcross-sectional view of the hemostasis valve assembly 18 of FIG. 2, ahemostasis valve or gasket 42 is positioned within a cavity 44 of thehub body 20 of the hemostasis valve assembly 18. The hemostasis valve 42may include one or more interlocking features configured to engagemating features on the hub body 20 to retain the hemostasis valve in adesired position and/or orientation within the hub body 20 (e.g., at afixed longitudinal and/or axial position within the cavity 44). Forexample, the hemostasis valve 42 may include a flanged outer perimeter46 configured to be received in a mating recess or groove 48 in the hubbody 20. The flanged outer perimeter 46 may have an increased thickness(e.g., in the proximal to distal direction, as shown in FIG. 3) relativeto a pair of annular grooves or recesses 54, 55 formed in the proximaland distal end surfaces of the hemostasis valve 42. It is contemplatedthat the hemostasis valve 42 may be assembled within the cavity 44 ofthe hub body 20 prior to assembly with an end cap 58 of the hemostasisvalve assembly 18. The end cap 58 may include a protrusion 56 configuredto engage the annular groove 54 of the hemostasis valve 42. The secondannular groove 55 may be configured to engage mating features, such as,but not limited to, a protrusion 57. The end cap 58 may frictionally orinterlockingly secure the flanged outer perimeter 46 within the groove48 and the annular grooves 54, 55 between the mating protrusions 56, 57.

During use (e.g., assembly of the dilator 14 with the introducer sheath12), the distal end 40 of the dilator 14 is advanced distally (e.g.,from a proximal side to a distal side of the hemostasis valve 42)through one or more slits in the hemostasis valve 42. The slits may bearranged to allow the hemostasis valve 42 to flex in the center, asdescribed in more detail herein. In order to reduce the force necessaryto advance the dilator 14 through the hemostasis valve 42, it may bedesirable for the dilator 14 to pass through the center of hemostasisvalve 42.

FIG. 4 illustrates a perspective view of the illustrative hemostasisvalve 42. The hemostasis valve 42 may have a generally cylindrical,puck-like body 41 having a proximal side 50 and a distal side 60. Thehemostasis valve 42 may be formed from an elastomeric silicone or othercompliant material which allows the hemostasis valve 42 to resume itsoriginal shape after temporary deformation (e.g., an applied stress orforce less than the yield point or fracture point). Some illustrativematerials may include, but are not limited to, a liquid silicone rubber(LSR) elastomer or enhanced tear resistant (ETR) silicone elastomers.

The proximal side 50 of the hemostasis valve 42 may include a tapered orconical central region 52 with the surface sloped towards the center ofthe hemostasis valve 42. The tapered central region 52 decreases indiameter from the proximal side 50 towards the distal side 60 of thehemostasis valve 42. The tapered central region 52 may guide the distalend 40 of the dilator 14 towards a diametrical center 53 of thehemostasis valve 42. The tapered central region 52 may act as aself-centering mechanism which automatically guides the distal end 40 ofthe dilator 14 (or other supplemental medical device) towards thediametrical center 53 of the hemostasis valve 42 as it is assembled withthe introducer sheath 12. The self-centering mechanism may facilitatedevice preparation before a procedure by reducing the force required topush the dilator 14 through the hemostasis valve 42 and/or reduce thenumber of attempts necessary to pass the dilator through the hemostasisvalve 42.

FIG. 5 illustrates a cross-sectional view of the hemostasis valve 42,taken at line 5-5 in FIG. 4. The distal side 60 of the hemostasis valve42 may include a distally extending curved or convex central region 62.The curvature of the curved central region 62 may help close thehemostasis valve 42 when blood, or other fluid, pushes against thedistal side 60 of the hemostasis valve 42. It is contemplated thatincreasing or decreasing the curvature of the curved central region 62may alter the effectiveness of the closure of the hemostasis valve 42.

As described herein, the flanged outer perimeter 46 may have anincreased thickness 51 relative to a pair of annular grooves or recesses54, 55 formed in the proximal and distal end surfaces of the hemostasisvalve 42. The flanged outer perimeter 46 may be thicker 51 than otherportions of the hemostasis valve 42 across the diameter thereof in orderprovide greater securement within the cavity 44 of the hub body 20. Thethickness of the hemostasis valve 42 may vary across the diameterthereof. For example, a thickness 43 adjacent to the annular grooves 54,55 may be greater than a thickness 45 adjacent to the diametrical center53 of the hemostasis valve 42. It is contemplated reducing the thicknessof the hemostasis valve 42 adjacent to the center 53 may reduce theforce required to advance a device through the hemostasis valve 42. Insome cases, the thickness 51 of the flanged outer perimeter 46 may bethe same as, similar to, or different from the other thicknesses 43, 45of the hemostasis valve 42, as desired. Other variations in thethickness(es) 43, 45, 51 of the hemostasis valve 42 are alsocontemplated. It is contemplated that changes in thickness may occur ina step-wise, or abrupt, manner or in a gradual, or smooth, manner, asdesired. In some cases, the thickness may be uniform across the diameterof the hemostasis valve 42.

FIG. 6A illustrates a proximal end view of the hemostasis valve 42having a slit configuration. The tapered central region 52 of the body41 may include a vertical slit 64 and a horizontal slit 66 extendinggenerally perpendicular to the vertical slit 64. The slits 64, 66 mayboth extend entirely through the thickness of the hemostasis valve 42from the proximal side 50 to the distal side 60 (e.g., in a cross slitthru (CST) configuration). Alternatively, the vertical slit 64 may beformed in the proximal side 50 of the hemostasis valve 42 and extenddistally partially through the thickness 45 between the tapered centralregion 52 and the curved central region 62. In such an instance, thehorizontal slit 66 may be formed in the distal side 60 of the hemostasisvalve 42 and extend proximally partially through the thickness 45between the tapered central region 52 and the curved central region 62.The slits 64, 66 may meet between the tapered central region 52 and thecurved central region 62 of the hemostasis valve 42 at theirintersection point 70 to define an opening extending entirely throughthe thickness of the hemostasis valve 42 (e.g., in a cross slit partial(CSP) configuration). In some cases, the intersection point 70 may be atthe diametrical center of the hemostasis valve 42, although this is notrequired The reverse configuration is also contemplated in which thehorizontal slit 66 is formed in the proximal side 50 of the hemostasisvalve 42 and extends distally partially through the thickness 45 betweenthe tapered central region 52 and the curved central region 62 and thevertical slit 64 is formed in the distal side 60 of the hemostasis valve42 and extends proximally partially through the thickness 45 between thetapered central region 52 and the curved central region 62. Other slitvariations are also contemplated. For example a first slit may extendthrough the thickness 45 between the tapered central region 52 and thecurved central region 62 while another slit may extend partially throughthe thickness 45 between the tapered central region 52 and the curvedcentral region 62.

The slits 64, 66 may intersect at the intersection point 70 to definefour flaps 68 a, 68 b, 68 c, 68 d (collectively, 68). The number andorientation of slits 64, 66 may be varied to vary a number of flaps 68,as desired. While the slits 64, 66 are described and shown as extendingin a horizontal and vertical orientation, it is contemplated that theslits 64, 66 may be rotated such that the slits 64, 66 are offset fromthe horizontal and vertical axes. It is further contemplated that theslits 64, 66 may not necessarily intersect at a 90° angle. Theintersection angle may be varied to create flaps 68 of varying size(e.g., two smaller and two larger). The flaps 68 may bend or flex in thedistal direction as the dilator 14 is passed through the hemostasisvalve 42. Once distal movement of the dilator 14 is ceased (and thedistal biasing force is removed from the hemostasis valve 42), thecurved central region 62 of the distal side 60 may bias the flaps 68proximally, causing the flaps 68 to seal around an outer surface of thedilator 14 as well as bringing the flaps 68 into intimate contactadjacent to the slits 64, 66.

FIG. 6B illustrates a proximal end view of the hemostasis valve 42having an alternative slit configuration. The tapered central region 52of the body 41 may include a plurality of slits 72 a, 72 b, 72 c, 72 d,72 e (collectively, 72). The slits 72 may be evenly distributed aboutthe tapered central region 52. For example, in the illustratedembodiments, the slits 72 may be spaced approximately 72° from oneanother. It is contemplated that the slits 72 may also be distributed atirregular intervals (e.g., not evenly spaced), as desired. The slits 72may extend entirely through the thickness of the hemostasis valve 42between the tapered central region 52 and the curved central region 62from the proximal side 50 to the distal side 60 (e.g., in a star slitthru (SST) configuration). In some embodiments, one or more of the slits72 may extend partially through the thickness of the hemostasis valve 42between the tapered central region 52 and the curved central region 62from either proximal side 50 or the distal side 60 thereof. It iscontemplated that all of the slits 72 may extend entirely through thethickness of the hemostasis valve 42 between the tapered central region52 and the curved central region 62, all of the slits 72 may extendpartially through the thickness of the hemostasis valve 42 between thetapered central region 52 and the curved central region 62 (from eitherthe proximal side 50, the distal side 60, or combinations thereof), orthe slits 72 may be a combination of slits that extend entirely orpartially through the thickness of the hemostasis valve 42 between thetapered central region 52 and the curved central region 62.

The slits 72 may intersect at an intersection point 76 to define fiveflaps 74 a, 74 b, 74 c, 74 d, 74 e (collectively, 74). The number andorientation of slits 72 may be varied to vary a number of flaps 74, asdesired. As described herein, the slits 72 may not necessarily intersectat a 72° angle. The intersection angles may be varied to create flaps 74of varying size. The flaps 74 may bend or flex in the distal directionas the dilator 14 is passed through the hemostasis valve 42. Once distalmovement of the dilator 14 is ceased (and the distal biasing force isremoved from the hemostasis valve 42), the curved central region 62 ofthe distal side 60 may bias the flaps 74 proximally causing the flaps 74to seal around an outer surface of the dilator 14 as well as bringingthe flaps 74 into intimate contact adjacent to the slits 72.

The materials that can be used for the various components of the medicaldevices and/or systems 10, 12, 14, 18, 42 (and/or other systemsdisclosed herein) and the various elements thereof disclosed herein mayinclude those commonly associated with medical devices. For simplicitypurposes, the following discussion makes reference to the system 10.However, this is not intended to limit the devices and methods describedherein, as the discussion may be applied to other elements, members,components, or devices disclosed herein, such as, but not limited to,the elongate shafts 16, 26 and the hemostasis valve assembly 18, and/orelements or components thereof.

In some embodiments, the system 10, and/or components thereof, may bemade from a metal, metal alloy, polymer (some examples of which aredisclosed below), a metal-polymer composite, ceramics, combinationsthereof, and the like, or other suitable material.

Some examples of suitable polymers may include polytetrafluoroethylene(PTFE), ethylene tetrafluoroethylene (ETFE), fluorinated ethylenepropylene (FEP), polyoxymethylene (POM, for example, DELRIN® availablefrom DuPont), polyether block ester, polyurethane (for example,Polyurethane 85A), polypropylene (PP), polyvinylchloride (PVC),polyether-ester (for example, ARNITEL® available from DSM EngineeringPlastics), ether or ester based copolymers (for example,butylene/poly(alkylene ether) phthalate and/or other polyesterelastomers such as HYTREL® available from DuPont), polyamide (forexample, DURETHAN® available from Bayer or CRISTAMID® available from ElfAtochem), elastomeric polyamides, block polyamide/ethers, polyetherblock amide (PEBA, for example available under the trade name PEBAX®),ethylene vinyl acetate copolymers (EVA), silicones, polyethylene (PE),Marlex high-density polyethylene, Marlex low-density polyethylene,linear low density polyethylene (for example REXELL®), polyester,polybutylene terephthalate (PBT), polyethylene terephthalate (PET),polytrimethylene terephthalate, polyethylene naphthalate (PEN),polyetheretherketone (PEEK), polyimide (PI), polyetherimide (PEI),polyphenylene sulfide (PPS), polyphenylene oxide (PPO), polyparaphenylene terephthalamide (for example, KEVLAR®), polysulfone,nylon, nylon-12 (such as GRILAMID® available from EMS American Grilon),perfluoro(propyl vinyl ether) (PFA), ethylene vinyl alcohol, polyolefin,polystyrene, epoxy, polyvinylidene chloride (PVdC),poly(styrene-b-isobutylene-b-styrene) (for example, SIBS and/or SIBS50A), polycarbonates, ionomers, biocompatible polymers, other suitablematerials, or mixtures, combinations, copolymers thereof, polymer/metalcomposites, and the like.

Some examples of suitable metals and metal alloys include stainlesssteel, such as 304V, 304L, and 316LV stainless steel; mild steel;nickel-titanium alloy such as linear-elastic and/or super-elasticnitinol; other nickel alloys such as nickel-chromium-molybdenum alloys(e.g., UNS: N06625 such as INCONEL® 625, UNS: N06022 such as HASTELLOY®C-22®, UNS: N10276 such as HASTELLOY® C276®, other HASTELLOY® alloys,and the like), nickel-copper alloys (e.g., UNS: N04400 such as MONEL®400, NICKELVAC® 400, NICORROS® 400, and the like),nickel-cobalt-chromium-molybdenum alloys (e.g., UNS: R30035 such asMP35-N® and the like), nickel-molybdenum alloys (e.g., UNS: N10665 suchas HASTELLOY® ALLOY B2®), other nickel-chromium alloys, othernickel-molybdenum alloys, other nickel-cobalt alloys, other nickel-ironalloys, other nickel-copper alloys, other nickel-tungsten or tungstenalloys, and the like; cobalt-chromium alloys; cobalt-chromium-molybdenumalloys (e.g., UNS: R30003 such as ELGILOY®, PHYNOX®, and the like);platinum enriched stainless steel; titanium; combinations thereof; andthe like; or any other suitable material.

As alluded to herein, within the family of commercially availablenickel-titanium or nitinol alloys, is a category designated “linearelastic” or “non-super-elastic” which, although may be similar inchemistry to conventional shape memory and super elastic varieties, mayexhibit distinct and useful mechanical properties. Linear elastic and/ornon-super-elastic nitinol may be distinguished from super elasticnitinol in that the linear elastic and/or non-super-elastic nitinol doesnot display a substantial “superelastic plateau” or “flag region” in itsstress/strain curve like super elastic nitinol does. Instead, in thelinear elastic and/or non-super-elastic nitinol, as recoverable strainincreases, the stress continues to increase in a substantially linear,or a somewhat, but not necessarily entirely linear relationship untilplastic deformation begins or at least in a relationship that is morelinear than the super elastic plateau and/or flag region that may beseen with super elastic nitinol. Thus, for the purposes of thisdisclosure linear elastic and/or non-super-elastic nitinol may also betermed “substantially” linear elastic and/or non-super-elastic nitinol.

In some cases, linear elastic and/or non-super-elastic nitinol may alsobe distinguishable from super elastic nitinol in that linear elasticand/or non-super-elastic nitinol may accept up to about 2-5% strainwhile remaining substantially elastic (e.g., before plasticallydeforming) whereas super elastic nitinol may accept up to about 8%strain before plastically deforming. Both of these materials can bedistinguished from other linear elastic materials such as stainlesssteel (that can also be distinguished based on its composition), whichmay accept only about 0.2 to 0.44 percent strain before plasticallydeforming.

In some embodiments, the linear elastic and/or non-super-elasticnickel-titanium alloy is an alloy that does not show anymartensite/austenite phase changes that are detectable by differentialscanning calorimetry (DSC) and dynamic metal thermal analysis (DMTA)analysis over a large temperature range. For example, in someembodiments, there may be no martensite/austenite phase changesdetectable by DSC and DMTA analysis in the range of about −60 degreesCelsius (° C.) to about 120° C. in the linear elastic and/ornon-super-elastic nickel-titanium alloy. The mechanical bendingproperties of such material may therefore be generally inert to theeffect of temperature over this very broad range of temperature. In someembodiments, the mechanical bending properties of the linear elasticand/or non-super-elastic nickel-titanium alloy at ambient or roomtemperature are substantially the same as the mechanical properties atbody temperature, for example, in that they do not display asuper-elastic plateau and/or flag region. In other words, across a broadtemperature range, the linear elastic and/or non-super-elasticnickel-titanium alloy maintains its linear elastic and/ornon-super-elastic characteristics and/or properties.

In some embodiments, the linear elastic and/or non-super-elasticnickel-titanium alloy may be in the range of about 50 to about 60 weightpercent nickel, with the remainder being essentially titanium. In someembodiments, the composition is in the range of about 54 to about 57weight percent nickel. One example of a suitable nickel-titanium alloyis FHP-NT alloy commercially available from Furukawa Techno Material Co.of Kanagawa, Japan. Other suitable materials may include ULTANIUM™(available from Neo-Metrics) and GUM METAL™ (available from Toyota). Insome other embodiments, a superelastic alloy, for example a superelasticnitinol can be used to achieve desired properties.

In at least some embodiments, portions or all of system 10, and/orcomponents thereof, may also be doped with, made of, or otherwiseinclude a radiopaque material. Radiopaque materials are understood to bematerials capable of producing a relatively bright image on afluoroscopy screen or another imaging technique during a medicalprocedure. This relatively bright image aids the user of the medicaldevice system 10 in determining its location. Some examples ofradiopaque materials can include, but are not limited to, gold,platinum, palladium, tantalum, tungsten alloy, polymer material loadedwith a radiopaque filler, and the like. Additionally, other radiopaquemarker bands and/or coils may also be incorporated into the design ofthe medical device system 10 to achieve the same result.

In some embodiments, a degree of Magnetic Resonance Imaging (MRI)compatibility is imparted into the medical device system 10. Forexample, system 10, and/or components or portions thereof, may be madeof a material that does not substantially distort the image and createsubstantial artifacts (e.g., gaps in the image). Certain ferromagneticmaterials, for example, may not be suitable because they may createartifacts in an MRI image. The system 10, or portions thereof, may alsobe made from a material that the MRI machine can image. Some materialsthat exhibit these characteristics include, for example, tungsten,cobalt-chromium-molybdenum alloys (e.g., UNS: R30003 such as ELGILOY®,PHYNOX®, and the like), nickel-cobalt-chromium-molybdenum alloys (e.g.,UNS: R30035 such as MP35-N® and the like), nitinol, and the like, andothers.

In some embodiments, an exterior surface of the medical device system 10(including, for example, an exterior surface of the delivery system) maybe sandblasted, beadblasted, sodium bicarbonate-blasted,electropolished, etc. In these as well as in some other embodiments, acoating, for example a lubricious, a hydrophilic, a protective, or othertype of coating may be applied over portions or all of the outer sheath,or in embodiments without an outer sheath over portions of the deliverysystem, or other portions of the medical device system 10. Hydrophobiccoatings such as fluoropolymers provide a dry lubricity which improvesdevice handling and device exchanges. Lubricious coatings improvesteerability and improve lesion crossing capability. Suitable lubriciouspolymers are well known in the art and may include silicone and thelike, hydrophilic polymers such as high-density polyethylene (HDPE),polytetrafluoroethylene (PTFE), polyarylene oxides,polyvinylpyrolidones, polyvinylalcohols, hydroxy alkyl cellulosics,algins, saccharides, caprolactones, and the like, and mixtures andcombinations thereof. Hydrophilic polymers may be blended amongthemselves or with formulated amounts of water insoluble compounds(including some polymers) to yield coatings with suitable lubricity,bonding, and solubility.

The coating and/or sheath may be formed, for example, by coating,extrusion, co-extrusion, interrupted layer co-extrusion (ILC), or fusingseveral segments end-to-end. The layer may have a uniform stiffness or agradual reduction in stiffness from the proximal end to the distal endthereof. The gradual reduction in stiffness may be continuous as by ILCor may be stepped as by fusing together separate extruded tubularsegments. The outer layer may be impregnated with a radiopaque fillermaterial to facilitate radiographic visualization. Those skilled in theart will recognize that these materials can vary widely withoutdeviating from the scope of the present invention.

It should be understood that this disclosure is, in many respects, onlyillustrative. Changes may be made in details, particularly in matters ofshape, size, and arrangement of steps without exceeding the scope of theinvention. This may include, to the extent that it is appropriate, theuse of any of the features of one example embodiment being used in otherembodiments. The invention's scope is, of course, defined in thelanguage in which the appended claims are expressed.

What is claimed is:
 1. A hemostasis valve for use in a medical device,the hemostasis valve comprising: a generally cylindrical body designedto be disposed within a hub body of a medical device, the body having aproximal side and a distal side; wherein the proximal side includes atapered central region having a surface sloped towards a diametricalcenter of the body; and wherein the distal side includes a distallyextending curved central region.
 2. The hemostasis valve of claim 1,wherein the body comprises an elastomeric silicone.
 3. The hemostasisvalve of claim 1, wherein the body comprises a liquid silicone rubber(LSR).
 4. The hemostasis valve of claim 1, wherein the body comprises anenhanced tear resistant (ETR) silicone elastomer.
 5. The hemostasisvalve of claim 1, further comprising one or more slits formed in thebody and extending at least partially through the body between thetapered central region and the curved central region of the body.
 6. Thehemostasis valve of claim 5, wherein the one or more slits are formed ina cross slit thru (CST) configuration.
 7. The hemostasis valve of claim5, wherein the one or more slits are formed in cross slit partial (CSP)configuration.
 8. The hemostasis valve of claim 5, wherein the one ormore slits are formed in a star slit thru (SST) configuration.
 9. Thehemostasis valve of claim 1, wherein the tapered central region isconfigured to guide a supplemental medical device to the diametricalcenter of the body.
 10. The hemostasis valve of claim 1, wherein thebody further comprises a flanged outer perimeter, the flanged outerperimeter configured to engage a hub body of a hemostasis valveassembly.
 11. A hemostasis valve assembly, comprising: a hub bodydefining a cavity; a strain relief portion extending distally from thehub body; an end cap coupled to a distal end of the hub body; and ahemostasis valve positioned within the cavity of the hub body andcoupled between the hub body and the end cap; wherein the hemostasisvalve comprises a generally cylindrical valve body having a proximalside including a tapered central region having a surface sloped towardsa diametrical center of the body and a distal side including a distallyextending curved central region.
 12. The hemostasis valve assembly ofclaim 11, wherein the valve body comprises an elastomeric silicone. 13.The hemostasis valve assembly of claim 11, wherein the valve bodycomprises a liquid silicone rubber (LSR).
 14. The hemostasis valveassembly of claim 11, wherein the valve body comprises an enhanced tearresistant (ETR) silicone elastomer.
 15. The hemostasis valve assembly ofclaim 11, further comprising one or more slits formed in the valve bodyand extending at least partially through the valve body between thetapered central region and the curved central region.
 16. The hemostasisvalve assembly of claim 11, wherein the valve body further comprises aflanged outer perimeter, the flanged outer perimeter configured toengage an interlocking groove in the hub body.
 17. The hemostasis valveassembly of claim 11, wherein the valve body further comprises a firstannular groove formed in the proximal side and a second annular grooveformed in the distal side, the first annular groove configured to engagean interlocking feature in the end cap and the second annular grooveconfigured to engage an interlocking feature in the hub body.
 18. Thehemostasis valve assembly of claim 11, wherein the tapered centralregion is configured to guide a medical device to the diametrical centerof the valve body.
 19. A hemostasis valve assembly, comprising: a hubbody defining a cavity; a strain relief portion extending distally fromthe hub body; an end cap coupled to a distal end of the hub body; and ahemostasis valve positioned within the cavity of the hub body andcoupled between the hub body and the end cap, the hemostasis valvecomprising: a generally cylindrical elastomeric valve body having aproximal side and a distal side; a tapered central region having asurface sloped towards a diametrical center of the valve body on theproximal side thereof; a distally extending curved central region on thedistal side thereof; a first annular groove formed in the proximal side;a second annular groove formed in the distal side; and a flanged outerperimeter.
 20. The hemostasis valve assembly of claim 19, furthercomprising one or more slits formed in the valve body and extending atleast partially through the valve body between the tapered centralregion and the curved central region.